In the summer of 2013, we got a call from the owner of a
2008 MINI Cooper S, an R56 model. She’d gotten in her car to go to work, and
her power steering wasn’t working. We
got the car in, and found a burnt steering motor (EPS) and a damaged high power
electrical connector. We replaced the
parts, checked the coding, verified that the steering worked, and sent her on
her way. We’ve replaced quite a few
steering motors so this one didn’t raise any eyebrows.
A year later the pump failed again. This time the connector actually melted
enough to separate from the steering motor.
When the owner tried to plug it back in the sparks told him to back
off. MINI supplied a new motor and
connector under parts warranty, and we changed them. Once again the steering worked. We thought it strange that the motor we
changed a year ago would fail.
A month later the owner drove the car to dinner and parked
it for the night at 8PM. Twelve hours
later – at 8 on a Sunday morning – a neighbor spotted smoke coming from the
MINI’s cowl. The owner opened the hood
to find a fire above the new EPS steering motor. It
seemed like it had gotten hot enough to start a fire. What was going on?
The car was examined by two forensic investigators, each
representing insurance companies that might be involved in settling the
claim. The first investigator’s job was
to learn whether the EPS started the fire, and if so, if there was a
workmanship error in its fitment. There was no error found. Installation of the motor is simple and
straightforward.
The second investigator built on the first investigator’s
findings, in an effort to further understand the cause of the fire. Both investigators agreed that the fire was
started by an overheated EPS unit. The
question was, why would the EPS overheat and start a fire after sitting
overnight? There is no circumstance
where the power steering motor should activate in a parked and locked car, 11
hours after it was parked for the night.
The EPS just sits there when the car is parked. It draws no power at rest, and should have been at ambient temperature by late that night.
A conversation with the owner revealed that this was a
pattern of failure. The steering never
failed when the car was in use. Instead,
the motors burned out while the car was parked.
The complaint was, “no steering when I got in the car,” as opposed to,
“the power steering quit while I was driving.”
We began to wonder how many other MINI owners had
experienced similar failures. We
searched our own service database and realized most MINI power steering
failures we’d seen were “in the morning” as opposed to “while driving.” An
Internet search raised quite a few more possibilities. And we read of some troubling and unexplained
fires in parked cars.
The investigation has ended – for now at least – with no
definite answer. The car’s insurance
will pay off, and the owner will get a new car.
We were never able to determine what woke the car’s electronics up and
caused it to start steering till it caught fire.
We were able to determine that the car slept most of the
night undisturbed. An analysis of the
charge in the battery told us how much energy the steering motor had
absorbed. A calculation told us how
rapidly that had to occur, to build enough heat to start a fire. Another calculation told us how fast the
steering could heat up, given the limitations of fuses and wiring. We determined that it woke up and started
trying to steer 30 minutes to an hour before catching fire.
That raised an interesting possibility. Could the car have been woken up by radio
signals, and come to life in an unexpected and destructive way? We know the pushbutton entry system can do more
than unlock the car. So can the radio
link that the BMW/MINI service and concierge people use. Might something have come into the car
through those channels? We don’t
know. It’s an idea, but without more
evidence we are stumped.
What’s your experience?
Do you know of a MINI that caught fire while parked, with no good
explanation?
Robison Service has provided independent service, repair, and restoration for BMW and MINI owners all over New England for over 25 years. Our company is an authorized Bosch Car Service Center. We also service Mercedes, Jaguar, Land Rover, Porsche, and Rolls Royce and Bentley motorcars. We have flatbed transport throughout the region. We also offer pickup and delivery for cars in Springfield, Wilbraham, Longmeadow, Agawam, Westfield, Northampton, and Amherst.
Posts
No comments:
Post a Comment